Operating mechanism for enclosed circuit breakers or switches



Sept. 10 1957 J. o. REXROAD SED CIRCUIT BREAKERS OR SWITCHES :5Sheetsfiheet 1 OPERATING MECHANISM FOR ENCLO Filed April 19, 1955 I I II I I II III IIII IIII IIIIIIII II II I I I I I IIII IIIII IIIII IIIIIII I I INVENTOR James O. Rexrood.

ATTORNEY I I a a a P a I A i I Id:

.......... J H v Q7. 9 41 W p 0 1957 J. o. REXROAD 2,806,099

OPERATING MECHANISM FOR ENCLOSED CIRCUIT BREAKERS OR SWITCHES FiledApril 19, 1955 3 Sheets-Sheet 2 36 g- I2 61 32 4 29 F a Flg I I 52 53 3729 3 F 67' 68 32 if" 55 4 34 2M 3 I? f T' i r' [L 25 fi 23 36 F lg. l4.

Sept. 10, 1957 J. o. REXROAD OPERATING MECHANISM FOR ENCLOSED CIFRCUITBREAKERS OR SWITCHES 3 Sheets-Sheet 3 Filed April 19, 1955 United StatesPatent OPERATING MECHANESM FDR ENCLOSED CIRCUIT BREAKERS 0R SWITCHESJames 0. Rexroad, Beaver, Pa., assignor to Westinghouse ElectricCorporation, East Pittsburgh, Pa., a corporation of PennsylvaniaApplication April 19, 1955, Serial No. 502,465 18 Claims. (Cl. 200-50)My invention relates, generally, to operating mechanisms for circuitinterrupters, such as automatic circuit breakers and manually operableswitches, which are mounted inside enclosing cabinets and, moreparticularly, to mechanisms having an operating handle mounted on thecover of the cabinet.

An object of my invention, generally stated, is to provide an operatingmechanism for an enclosed circuit interrupter which shall be simple andeflicient in operation and which may be economically manufactured andinstalled.

A more specific object of my invention is to provide an operatingmechanism which may be readily adapted to enclosures of various depths.

Another object of my invention is to provide an operating mechanism foran enclosed circuit interrupter which does not require accuratealignment of the parts of the mechanism for satisfactory operation ofthe mechanism.

A further object of my invention is to provide an operating mechanismhaving an external handle which is self-aligning with the position ofthe interrupter handle inside the cover.

Still another object of my invention is to provide a simplified andimproved cover interlocking device which does not require adjustment tomaintain satisfactory operation after being installed.

A still further object of my invention is to provide means for releasingthe cover interlock except when the switch is locked in the offposition.

Yet another object of my invention is to provide an operating mechanismhaving the following features:

(a) The cover is slam-proof; that is, it may be slammed closed withoutdamaging the circuit interrupting device.

(b) The cover cannot be closed without the external handle giving apositive indication of the position of the device handle.

(0) A cover interlock is supplied which does not require adjustment. Theinterrupting device must be 01f to open the cover, except as noted in(d).

(d) A means of defeating the cover interlock is available if the featureis desired.

(e) The external handle will not operate the interrupting device beforethe cover interlock is engaged.

(f) The device can be locked off with a number of padlocks having haspsof different sizes.

(g) When the device is locked oif the cover is also locked closed andthe cover interlock defeating means is covered by the handle.

(11) A means of locking the device on is available if desired.

(i) The mechanism can be mounted on covers of different thicknesseswithout special adapters or adjustment.

(j) The mechanism can be adapted for use with special cover latches forlarge cabinet doors where it is desirable to latch at the edges.

(k) Provision is made for complete gasketing against the entrance ofoil, etc. into the enclosure.

Other objects of my invention will be explained fully hereinafter orwill be apparent to those skilled in the art.

In accordance with one embodiment of my invention, an operating handleis rotatably mounted in a hub which is attached to the outer surface ofthe cover for a cabinet which encloses a circuit interrupting device.Actuating means for opening and closing the circuit interrupter ismounted inside the cabinet and connected to the handle by means of ashaft, one end of which enters a recess in the handle when the cover isclosed. The other end of the shaft is spring mounted to permit universalmovement of the end which enters the handle. A springbiased interlockinglatch is pivotally mounted in the hub and engages a shoulder on theshaft to prevent opening the cover except when the handle is in the opencover position. A locking lever is pivotally mounted in the handle andpadlocks may be fastened on the handle to lock the handle in the offposition by means of the locking lever. A projection on the lockinglever prevents access to cover releasing means when the handle is lockedin the off position.

For a better understanding of the nature and objects of the invention,reference may be had to the following detailed description, taken inconjunction with the accompanying drawings, in which:

Figure 1 is a view, partly in side elevation and partly in section, of acabinet and mechanism for operating a circuit interrupting devicemounted inside the cabinet, the handle of the operating mechanism beingshown in the on position;

Fig. 2 is a view, in bottom plan, of the handle and mounting hub withtthe handle in cover position;

Fig. 3 is a view, in front elevation, taken along the line III-III inFig. 1;

Fig. 4 is a view, in section, assembly, the handle being locked in theoff position;

Figs. 5 and 6 are views, in plan and side elevation, respectively, of aspring for retaining the interlocking latch in the hub;

Figs. 7 and 8 are views, in elevation and plan, respectively, of theinterlocking latch;

Fig. 9 is a view, partly in section and partly in front elevation, ofthe actuating mechanism for actuating the operating member of thecircuit interrupter, the section being taken along the line IX-IX inFig. 1;

Fig. 10 is a view, partly in section and partly in plan, of the handleassembly and actuating mechanism, the handle being midway between offand on positions;

Fig. 11 is a view, in section, of the actuating mechanism and itssupporting frame;

Fig. 12 is a view, in bottom ating handle;

Fig. 13 is a view, in bottom plan, of the locking lever;

Fig. 14 is a view, in bottom taining washer and cam;

Fig. 15 is a view, in top plan, of the hub for the external operatinghandle;

Fig. 16 is a View, in bottom in Fig. 15; and

Fig. 17 is a view similar to Fig. 15, showing modifications in the hubstructure.

Referring to the drawings, and particularly to Fig. 1, the structureshown therein comprises a sheet metal cabinet 10 having a cover 11attached to the cabinet by means of hinges (not shown). An externaloperating handle 12 is rotatably mounted in a hub 13 which may beattached to the cover 11 by screws 14 inserted in tapped holes 14 in thehub 13. As will be more fully described hereinafter, the handle 12 isutilized for operoperating the open of a portion of the handle plan, ofthe external operplan, of a combined replan, of the hub shown a'ting theswitch or circuit breaker mounted inside the cabinet 10.

The circuit breaker 15 may be of the type described in Patent No.2,047,739, issued to H. I. Lingal, July 14, 1936, and assigned to theassignee of the present invention. The circuit breaker 15 is providedwith contact members (not shown) and an operating mechanism for openingand closing the contact members by means of anoperating member 16. Asdescribed in the aforesaid patent, the circuit breaker is also providedwith a tripping mechanism which is operable in response to predeterminedoverload currents to effect automatic opening of the contact members.

As previously mentioned, the contact members of the circuit breaker maybe manually opened and closed by oscillatory movement of the operatingmember 16 which is actuated by movement of the external operating handle12. As indicated in Fig. 3, the operating handle 12 may be moved to anon position to close the contact members of the circuit breaker15. The.handle 12 may be moved to an off position to open the contact membersof the circuit breaker. The handle 12 is automatically moved to aposition substantially midway between the off and the on positions whenthe contact members of the circuit breaker are opened by the overloadtripping mechanism.

As will be described more fully hereinafter, the handle 12 maybe movedto an open cover position in order to permit the opening of the cover 11of the cabinet 10. The handle 12 may also be moved to, or slightly,beyond the open cover position and then to the on position in order toreclose the contact members of the breaker after they have been openedby the tripping mechanism.

As shown most clearly in Figs. 9, 10 and 11, the operating member 16 ofthe circuit breaker 15 is actuated by an actuating plate 17 havingspaced arms 18 for engaging the member 16 The actuating plate 17 issecured to a sleeve 19 by welding or other suitable means. The lower endof the sleeve 19 is rotatably mounted in a bearing plate 21. The bearingplate 21 and a bracket 22 are at tached to a generally U-shaped frame 23by screws 24. The plate 21 may also be attached to the bracket 22 bybolts or rivets 25. As shown in Fig. 10, the frame 23 may be attached tothe bottom wall of the cabinet 10. This may be done by utilizing thebreaker mounting screws which may extend through clearance holes in theframe 23.

As shown most clearly in Fig. 11, a shaft 26 is threaded into thebearing sleeve 19. As shown by the broken lines, the shaft 26 is scoredat predetermined intervals 27 when it is manufactured to permit portionsof the shaft to be removed to obtain approximately the desired lengthwhen the operating mechanism is installed in the housing 10. Thus, theshaft may be utilized inhousings having various depths. The surplusportion of the shaft must be removed before it is threaded into thesleeve 19. The shaft may be adjusted longitudinally by means of thethreaded sleeve, thereby securing the proper height of the upper end ofthe shaft for engagement by the handle 12 when the cover 11 is fullyclosed to insure proper operation of the actuating mechanism. After theshaft 26 is .properly adjusted, it is retained in the correct positionby means of a set screw 28. The upper end of the shaft 26 has aconically-shaped end '29 and a shoulder 31 below the conical portion 29.A pin 32 is inserted transversely through the shaft 26.

'22 for the sleeve 19 is of a larger diameter than the sleeve 19. Thus,the upper end of the shaft 26 may move a predetermined amount from avertical position to permit the upper end of the shaft to enter a recess36 in the handle 12, even though the recess 36 is out of alignment withthe lower end of the shaft. A slot 37 is provided in the handle 12 forreceiving the pin 32. As shown in Figs. 10 and 12, sloping surfaces 38are provided in the handle 12 for guiding the pin 32 into the slot 37 asthe shaft enters the recess 36. In this manner, a certain amount ofmisalignment is permitted between the shaft 26 and the handle 12,thereby facilitating the installation of the operating mechanism incabinets having small manufacturing errors.

A torsion spring 39 is also provided around the sleeve 19. One end ofthe spring 39 is connected to the bracket 22 and the other end isconnected to the sleeve 19 to bias the handle 12 toward the on positionwhen the cover is closed. In this manner, the weight of the handle 12 iscounteracted when the cabinet is mounted in the vertical position shownin the drawings, thereby keeping the handle in the full on position whenthe circuit breaker or switch is closed.

As previously stated, the handle 12 is rotatably mounted in the hub 13which is attached to the outer surface of the cover 11 by screws 14. Thehandle 12 is retained in the hub 13 by means of a washer 41 which alsofunctions as a cam to release an interlocking device as well beexplained more fully hereinafter. The washer 41 is attached to thehandle 12 by means of screws 42 which e);- tend through openings 43 inthe washer into tapped holes 44 in the handle 12. As shown in Fig. l0,the washer 41 engages a shoulder 45 on the hub 13 to retain the handle12 in position. A gasket 46 may or may not be provided around theopening in the 'hub 13 for the handle 12, thereby preventing dirt andother foreign matter from entering the cabinet around the handle when itis used. A gasket 47 may be provided between the hub 13 and the cover11. A gasket 4-3 is also provided for around an opening 49 in the hub 13which is provided for defeating the interlocking device, as will bedescribed hereinafter.

As shown most clearly in Fig. 15, a torsion spring 51, which is mountedin the handle 12 as shown in Fig. 10, is disposed in the hub 13 when thehandle and the hub are assembled together to bias the handle 12 to aposition substantially midway between the on and the ofi? positions whenthe cover 11 is open, and the cabinet is mounted vertically as shown inFig. 1. The torsion spring 51 engages a projection 52 on the hub 13 anda projection 53 on the handle .12 to overcome the weight of the handleand ;bias the handle to its mid position. in this manner, the handle isretained in its mid position when the cover is open, thereby causing thepin 32 in the shaft26 to engage the sloping surfaces 38 in the handleand guide the 13111111110 the slot 37 as the cover is being closed.Thus, breakage of any of the parts by slamming the cover with the handlein an improper position is prevented. When the cover is closed, thehandle is actuated by the pin 32 to its proper position in accordancewith the position of the breaker. handle 16 or the operating member ofthe switch. If the cabinet is to be mounted horizontally, adouble-acting spring may be substituted for the single acting spring 51.V 7

As previously explained, an interlocking device is provided to normallyprevent opening the cover 11 except when the handle 12 is actuated tothe open cover position. As shown most clearly in Fig. 16, aninterlocking latch 54 is pivotally mounted in the hub 13. Oneend 55oftheiatch 54 pivots in a recess in the hub 13. The other end 56 of thelatch 54 is biased by a spring 57 to aposition underneath the shoulder31 on the shaft 26 when the cover is closed.

Thus, the end 56 of the latch 54 engages the shoulder 31 on the shaft 26to prevent opening the cover 11 when the handle 12 is in the on positionand the contact members of the breaker are closed. The latch-54 stillengages the shoulder 31 when the handle is in the o position and thecontact members of the breaker are open. However, when the handle 12 isactuated to the open cover position, a cam portion 60 on the washer 41engages a pin 53 on the latch 54 to release the latch from engaging theshoulder 31, thereby permitting the cover to be opened.

As explained hereinbefore, the latch 54 may be released by an authorizedperson to defeat the interlock when the handle is in the on position andthe breaker is closed, thereby permitting inspection of the equipmentinside the cabinet. This may be accomplished by inserting a screwdriveror other tool through the opening 49 into a groove 59 provided in thelatch 54 and turning the screwdriver. Thus, the latch may be actuated todisengage the shaft 26 and permit the cover to be opened.

The latch 54 is retained in the hub by a spring 61 which is attached tothe hub by a screw 62 inserted through an opening 63 in the spring andthreaded into a tapped hole 64 in the hub 13. The spring 61 has an arm65 which engages the latch 54 to retain the latch in the hub 13. Thespring 61 has another arm 66 which covers the spring 57 to retain it inposition in the hub 13. The spring 61 is shown in detail in Figs. 5 and6. The latch 54 is shown in detail in Figs. 7 and 8 of the drawings. Thecamming washer 41 is shown in detail in Fig. 14.

A locking lever 67 is pivotally mounted in the handle 12 in order thatthe handle may be locked in the off position, thereby preventing theclosing of the circuit breaker or switch. As shown in Fig. 10, the lever67 is normally biased to its uppermost position by a compression spring68. When the handle 12 is in the off position, the lever 67 may bedepressed into a slot 69 in the hub 13. As shown in Fig. 4, a hasp 71 of.a padlock may be installed around the handle 12 between the lever 67and the handle to retain the lever in the slot 69. Thus, the handle maybe locked in the off position to prevent closing the circuit breaker orswitch. As previously explained, the cover 11 cannot be opened when thehandle 12 is in the off position. Therefore, access cannot be gained tothe inside of the cabinet to close the circuit breaker.

As shown most clearly in Fig. 13, the lever 67 has a laterally extendingprojection 67' which covers the opening 49 in the hub 13 when the handle12 is in the off position. Therefore, a screwdriver or other tool cannotbe inserted into the opening 49 to release the interlocking latch 54 topermit opening the cover 11. Accordingly, the interlock cannot bedefeated when the handle 12 is locked in the off position. In thismanner, a workman or other person who installs his padlock on the handle12 to lock the switch 01 is assured that the switch cannot be closedwhile his padlock is installed. It will be noted that space is providedfor the installation of several padlocks on the switch handle at thesame time. Therefore, each one of a group of workmen can lock the switchoff with his own padlock.

Provision for locking the switch in the on position may be made byremoving a small amount of metal 72 from the has. 13 to permit the lever67 to enter a slot 73 provided in the hub 13. The open slot 73 is shownin Fig. 17. As previously explained, the cover 11 is normal- 1y retainedclosed by the interlocking latch 54 when the handle is in the onposition. However, the interlocking latch 54 may be released by means ofa screwdriver as previously explained. The opening 49 is not covered bythe projection 67 on the locking lever 67 when the handle 12 is in theon position. If the interlocking release is not desired, a knock-out 49may be left in the hub 13, as shown in Fig. 17, thereby leaving theopening closed and preventing operation of the latch 54 from theexterior of the cabinet.

While the invention has been described using the designations on and 011and open cover for the positions as shown in Figs. 3 and 15, it is to beunderstood 6 that other nomenclature could be used. For example, theposition marked open cover is also an off position and could be somarked. Then, the position marked off could be marked lock meaning thatthe switching device is to be locked off and the cover is locked closedin that position.

When the operating mechanism is utilized on cabinets having unusuallylong covers, additional means may be provided for locking the ends ofthe cover closed. As shown most clearly in Fig. 1, a latch 74 ispivotally mounted on a bracket 75 attached to the cover 11. The latch 74is disposed to engage an angle member 76 attached to one end of thecabinet 10 to retain the cover closed. The latch 74 is actuated topermit the cover to be opened by means of a link 77 which is connectedto a lever 78 roratably mounted on a rivet 79 in the cover 11. The lever78 is actuated by a pin 81 secured to the interlocking latch 54. Thus,the latch 74 is actuated to permit the cover 11 to be opened when theinterlocking latch 54 is actuated to disengage the shaft 26. As shown,the lever 78 is provided with several arms 82 to permit the operation ofadditional latches similar to the latch 74 if it is desired to installadditional latches. In this manner, the ends of long covers areprevented from being pried open to gain access to the interior of thecabinet.

It will be noted that the frame 23 and the actuating mechanism supportedby the frame may be mounted in the cabinet independently of the circuitbreaker unit 15. Thus, the breaker may be removed without it beingnecessary to remove the actuating mechanism. Furthermore, the parts ofthe actuating mechanism comprising the plate 17, the shaft 26, thebearing sleeve 19, the springs 33 and 39, and the washer 34 may beassembled in the bearing plate 21 and the bracket 22 as a unit. Thisunit may be attached to the frame 23 after the frame 23 is installed inthe cabinet 10. The handle assembly comprising the hub 13 and the handle12 may be installed on the lid of the cabinet by means of the screws 14as previously explained. As also previously explained, the shaft 26 maybe adjusted longitudinally to permit the mechanism to be installed incabinets of various depths. The shaft should be so adjusted that the pin32 is past the sloping surfaces 38 and in the slot 37 when the cover 11is fully closed.

Furthermore, universal movement of the upper end of the shaft ispermitted by the spring 33 to obtain satisfactory operation of themechanism without accurate alignment between the shaft 26 and the handle12. The thickness of the cover 11 will not affect the operation of themechanism. With extremely thick covers, it may be necessary to providelonger screws 14 for attaching the hub 13 to the cover. The longitudinaladjustment of the shaft 26 will compensate for variations in thethickness of the cover 11. The proper engagement of the interlockinglatch 54 with the shoulder 31 is obtained by making the distance fromthe shoulder 31 to the centerline of pin 32 correct when they aremanufactured. When the cover is being closed, latch 54 engages beforethere is enough engagement between pin 32 and sloping surfaces 38 toallow the breaker to be operated to the on position by movement of thehandle 12.

From the foregoing description it is apparent that I have provided amechanism for operating enclosed circuit breakers or switches which isrelatively simple in construc tion. The mechanism provides all thesafety interlocking features considered desirable in such a mechanism.The present mechanism i particularly suitable for installation incabinets or housings which are not supplied by the manufacturer of thecircuit breakers or switches and the handle operating mechanism. Asexplained, the mechanism may be installed in cabinets of various depths,and close manufacturing tolerances do not have to be maintained in orderto secure proper operation of the mechanism.

Since numerous changes may be made in the above described construction,and different embodiments of the invention may be made without departingfrom the spirit and scope thereof, it is intended that all matter Con- 7tained in the foregoing description or shown in the accompanying drawingshall be interpreted as illustrative and not in .a limiting sense.

' Iclairn as my invention: 7 a a l. Incombination, a circuit interrupterhaving a movable operating member for opening and closing theinterrupter, a cabinet in which the interrupter is mounted in a fixedposition, an openable cover for the cabinet, an external operatinghandle rotatably mounted on the cover, actuating means disposed insidethe cabinet separately from the int rrupter and operated by said handleto actuate the operating member of the interrupter, a rotatable shaftinterconnecting said actuating means and said handle, said shaft havingone end engaged by said handle when the cover is closed, spring means atthe other end of the shaft to permit universal movement of the endengaged by the handle, and said shaft being adjustable in length for usein cabinets .of various depths.

2. in combination, a circuit interrupter having a movable operatingmember for opening and closing the interrupter, a cabinet in which theinterrupter is mounted in a fixed position, an c-penable cover for thecabinet, an external operating handle rotatably mounted on the cover,actuating mean disposed inside the cabinet separately from theinterrupter and openated by said handle to actuate the operating memberof the interrupter, a rotatable shaft interconnecting said actuatingmeans and said handle, said shaft having one end engaged by said handlewhen the cover is closed, and spring means at the other end of the shaftto permit universal movement of the end of the shaft engaged by thehandle.

3. In combination, a circuit interrupter having a movable operatingmember for opening and closing the interrupter, a cabinet in which theinterrupter is mounted in a fixed position, an openable cover for thecabinet, an external operating handle rotatably mounted on the cover,actuating means disposed inside the cabinet and operated by said handleto actuate the operating member of the interrupter, a rotatable shaftinterconnecting said actuating means and said handle, said shaft havingone end engaged by said handle when the cover is closed, supportingmeans fixed in the cabinet for supporting the other end of the shaft,and said shaft being adjustable longitudinally in said supporting means.

4. In combination, a circuit interrupter having a movable operatingmember for opening and closing the interrupter, .a cabinet in which theinterrupter is mounted in a fixed position, an openable cover for thecabinet, an external operating handle rotatably mounted on the cover,actuating means disposed inside the cabinet and operated by said handleto actuate the operating member of the interrupter, a rotatable shaftinterconnecting said actuating means and said handle, said shaft havingone end engaged by said handle when the cover is .closed, supportingmeans fixed in the cabinet .for supporting the other end of the shaft,and spring means surrounding the end of the shaft at said supportingmeans to permit lateral movement of the end of the shaft engaged by thehandle.

5.. In combination, a circuit interrupter having a movable operatingmember for opening and closing the interrupter, a cabinet in which theinterrupter is mounted in .a fixed position, an openable cover for thecabinet, an external operating handle rotatably mounted on the cover,actuating means disposed inside the cabinet and operated by said handleto actuate the operating member of the interrupter, a rotatable shaftinterconnecting said actuating means and said handle, said shaft havingone end engaged by said handle when the cover is closed, supportingmeans fixed in the cabinet for supporting the other end of the shaft,said supporting means permitting lateral movement of the end of theshaft engaged by the handle, and a torsion spring for biasing said shaftto counteract .the weight of the handle when the handle engages-theshaft.

6. In combination, a circuit interrupter having a movable operatingmember for opening and closing the interrupter, a cabinet in which theinterrupter is mounted in a fixed position, an openable cover for thecabinet, an external operating handle rotatably mounted on the cover,actuating means disposed inside the cabinet and operated by said handleto actuate the operating member of the interrupter, a rotatable shaftinterconnecting said actuating means and said handle, said shaft havingone end en gaged by said handle when the cover is closed, supportingmeans fixed in the cabinet for supporting the other end of the shaft,and threaded means for adjusting said shaft longitudinally in saidsupporting means.

7. A mechanism for operating a circuit interrupter mounted inside acabinet having an openable cover comprising a hub for attaching to thecover, a handle rotatably mounted in the hub, actuating means formounting inside the cabinet to actuate the circuit interruptena rotatable shaft interconnecting said actuating means and said handle, saidhandle having a recess therein for receiving one end of said shaft whenthe cover is closed, an interlocking latch pivotally mounted in said hubto engage the shaft to prevent opening the cover, and cam means movablewith the handle for actuating said latch to permit opening the'coverwhen the handle is in a predetermined position.

8. A mechanism for operating a circuit interrupter mounted inside acabinet having an openable cover comprising a hub for attaching to thecover, a handle rotatably mounted in the hub, actuating means formounting inside the cabinet to actuate the circuit interrupter, arotatable shaft interconnecting said actuating means and said handle,said handle having a recess therein for receiving one end of said shaftwhen the cover is closed, an interlocking ilatch pivotally mounted insaid hub and biased by a spring to engage the shaft to prevent openingthe cover, and a washer attached to said handle to retain the handle insaid hub, said Washer having a cam surface for actuating said latch topermit opening the cover when the handle is in a predetermined position.

9. A mechanism for operating a circuit interrupter mounted inside :acabinet having an openable cover comprising a hub for attaching to thecover, a handle rotatably mounted in the hub, actuating means formounting inside the .cabinet to actuate the circuit interrupter, arotatable shaft interconnecting said actuating means and said handle,said handle having a recess therein for receiving one end of said shaftwhen the cover is closed, an interlocking latch pivotally mounted insaid hub to engage the shaft to prevent opening the cover, and cam meansmovable with the handle for actuating said latch to permit opening thecover when the handle is in a predetermined position, releasing means inthe'hub accessible from out side the cabinet for actuating said latchindependently of said cam means, and means movable with the handle forpreventing access to said releasing means when the handle is in apredetermined position.

10. A mechanism for operating a circuit interrupter mounted inside .acabinet having .an openable cover comprising a hub for attaching to thecover, a handle rotatably mounted in the hub, actuating means formounting inside the cabinet to actuate the circuit interrupter, arotatableshaft interconnecting said actuating means and said handle,said handle having a recess therein for receiving one end of said shaftwhen the cover is closed, an interlocking latch pivotally mounted insaid hub to engage the shaft to prevent opening the cover, cam meansmovable with the handle for actuating said latch to permit open ing thecover when the handle is in a predetermined position, and a lockinglever pivotally mounted in said handle for engaging said hub to retainthe handle in a predetermined position.

11. A mechanism for operating a circuit interrupter mounted inside acabinet having an openable cover comprising a hub for attaching to thecover, a handle rotatably mounted in the hub, actuating means formounting inside the cabinet to actuate the circuit interrupter, arotatable shaft interconnecting said actuating means and said handle,said handle having a recess therein for receiving one end of said shaftwhen the cover is closed, an interlocking latch pivotally mounted insaid hub to engage the shaft to prevent opening the cover, and cam meansmovable with the handle for actuating said latch to permit opening thecover when the handle is in a predetermined position, releasing means inthe hub accessible from outside the cabinet for actuating said latchindependently of said cam means, a locking lever pivotally mounted insaid handle for engaging said hub to retain' the handle in apredetermined position, and blocking means on said lever for preventingaccess to said releasing means when the handle is locked in apredetermined position.

12. A mechanism for operating a circuit interrupter mounted inside acabinet having an openable cover comprising a hub for attaching to thecover, a handle rotatably mounted in the hub, actuating means formounting inside the cabinet to actuate the circuit interrupter, arotatable shaft interconnecting said actuating means and said handle,said handle having a recess therein for receiving one end of said shaftwhen the cover is closed, an interlocking latch pivotally mounted insaid hub to engage the shaft to prevent opening the cover, cam meansmovable with the handle for actuating said latch to permit opening thecover when the handle is in a predetermined position, and additionallatching means actuated by said latch to engage the cabinet.

13. A mechanism for operating a circuit interrupter mounted inside acabinet having an openable cover comprising a hub for attaching to thecover, a handle rotatably mounted in the hub, actuating means formounting inside the cabinet to actuate the circuit interrupter, arotatable shaft connected to said actuating means and engaged by saidhandle when the cover is closed, an interlocking latch disposed toprevent opening the cover, cam means movable with the handle foractuating said latch to permit opening the cover when the handle is in apredetermined position, releasing means for actuating said latchindependently of said cam means, and knock-out means removable from saidhub to permit access to said releasing means from outside the cabinet.

14. A mechanism for operating a circuit interrupter mounted inside acabinet having an openable cover comprising a hub for attaching to thecover, a handle rotatably mounted in the hub, actuating means formounting inside the cabinet to actuate the circuit interrupter, arotatable shaft connected to said actuating means and engaged by saidhandle when the cover is closed, an interlocking latch disposed toprevent opening the cover, said latch being disengaged to permit openingthe cover when the handle is in a predetermined position, releasingmeans for actuating said latch at other positions of the handle, andknock-out means removable to permit access to said releasing mans fromoutside the cabinet.

15. In combination, a circuit interrupter having a movable operatingmember for opening and closing the interrupter, a cabinet in which theinterrupter is mounted in a fixed position, an openable cover for thecabinet, an external operating handle rotatably mounted on the cover,actuating means disposed inside the cabinet and operated by said handleto actuate the operating member of the interrupter, said actuating meansbeing unattached to the interrupter except by engagement with theoperating member, a rotatable shaft interconnecting said actuating meansand said handle, said shaft having one end engaged by said handle whenthe cover is closed and said shaft being adjustable in length for use incabinets of various depths.

l6. In combination, a circuit interrupter having a movable operatingmember for opening and closing the interrupter, a cabinet in which theinterrupter is mounted in a fixed position, an openable cover for thecabinet, an operating handle externally mounted on the cover, actuatingmeans disposed inside the cabinet and operated by said handle to actuatethe operating member of the interrupter, interlocking means disposed toprevent opening the cover, said interlocking means being disengaged topermit opening the cover when the handle is in a predetermined position,releasing means for disengaging the interlocking means at otherpositions of the handle, and removable means for permitting access tosaid releasing means from outside the cabinet.

17. In combination, a circuit interrupter having a movable operatingmember for opening and closing the interrupter, a cabinet in which theinterrupter is mounted in a fixed position, an openable cover for thecabinet, an operating handle externally mounted on the cover, actuatingmeans disposed inside the cabinet and operated by said handle to actuatethe operating member of the interrupter, interlocking means disposed toprevent opening the cover, said interlocking means being disengaged topermit opening the cover when the handle is in a predetermined position,releasing means for disengaging the interlocking means at otherpositions of the handle, and removable means for making said releasingmeans operable from outside the cabinet.

18. In combination, a circuit interrupter having a movable operatingmember for opening and closing the interrupter, a cabinet in which theinterrupter is mounted in a fixed position, an openable cover for thecabinet, an operating handle externally mounted on the cover, actuatingmeans disposed inside the cabinet and operated by said handle to actuatethe operating member of the interrupter, interlocking means disposed toprevent opening the cover, said interlocking means being disengaged topermit opening the cover when the handle is in -a predeterminedposition, releasing means for disengaging the interlocking means atother positions of the handle, and means accessible from outside thecabinet for changing the operativeness of said releasing means.

References Cited in the file of this patent UNITED STATES PATENTS2,324,543 Scott July 20, 1943 2,364,465 Myers Dec. 5, 1944 2,364,480Schymik Dec. 5, 1944 2,703,829 Lingal Mar. 8, 1955

